Carbon-14 urea breath test for the diagnosis of Campylobacter pylori associated gastritis

Urease in the human gastric mucosa is a marker for infection with Campylobacter pylori (CP), an organism suspected of causing chronic gastritis and peptic ulceration. To detect gastric urease, we examined 32 patients who were being evaluated for possible peptic ulcer disease. Fasting patients were given 10 μCi (370 kBq) of ¹⁴C-labeled urea. Breath samples were collected in hyamine at intervals between 1 and 30 min. The amount of ¹⁴C collected at these times were expressed as: body weight x (% of administered dose of ¹⁴C in sample)/(mmol of CO₂ collected). The presence of C. pylori colonization was also determined by examination of multiple endoscopic gastric biopsy specimens. On average, patients who were proven to have C. pylori infection exhaled 20 times more labeled CO₂ than patients who were not infected. The difference between infected patients and C. pylori negative 'control' patients was highly significant at all time points between 2 and 30 min after ingestion of the radionuclide (p < 0.0001). The noninvasive urea breath is less expensive than endoscopic biopsy of the stomach and more accurate than serology as a means of detecting Campylobacter pylori infection. Because the test detects actual viable CP organisms, it can be used to confirm eradication of the bacterium after antibacterial therapy.